Cancer is the second most common cause of death in the US, accounting for nearly 1 of every 4 deaths. In 2009, more than 1,500 people died of cancer each day, claiming approximately 562,340 deaths of Americans entirely. The National Institutes of Health estimates overall costs of cancer in 2008 at $228.1 billion with $93.2 billion for direct medical costs (total of all health expenditures), $18.8 billion for indirect morbidity costs (cost of lost productivity due to illness), and $116.1 billion for indirect mortality costs (cost of lost productivity due to premature death).
Conventional cancer therapy has been focused on non-specific cytotoxic and/or radiation therapy, based on the observation that malignant cells divide at a more rapid rate than the normal cells. For example, ionizing radiation induces DNA damage that, upon multiple cell divisions, may lead to errors in transcription and translation resulting in cell death. Similarly, cytotoxic chemotherapy may interrupt microtubule formation that is essential for mitotic events, and ultimately affect cell survival. The conventional therapies have resulted in significant survival advantages in breast and colon cancer patients.
Despite the above noticed benefits, conventional therapies directed against rapidly dividing cells may also result in the death of epithelium (such as the lining of the gastrointestinal tract) or affect hematopoietic progenitors, resulting in cytopenia. These side effects not only reduce the quality of life of cancer patients, but also limit the dosage available for therapy, ultimately resulting therapeutic antitumor activity.
Recently, targeted cancer therapies emerge to direct at the molecular pathways that underlie the malignant phenotype. These therapies target specific tumor cell receptors or signaling events that are critical to tumor progression while reducing toxicity to normal cells.
One limiting factor for targeted cancer therapy is to identify the right tool and monitor its effect on tumor suppression. For example, for most cancers that have metastasized it is urgent to have early effective diagnostic tools, so that physicians are able to replace ineffective therapies with potentially more effective therapies. The selection of the appropriate therapy remains a difficult decision for physicians. To accurately assess the effect of any cancer treatment, reliable device and method are needed for continuous monitoring of the cancer patient. Therefore, an early and accurate detection method, which facilitates physicians to effectively characterize the cancers and outline the treatment, will save many lives.
This disclosure provides a general tool to effectively select the target cancer patient population, stratify the cancer progression, determine the appropriate cancer therapy, monitor the effect of treatment for personalized cancer diagnostics and therapeutics, and/or identify molecular pathways of any specific malignant phenotype for the discovery of potent pharmaceuticals.